Process of treating casein-varnish-finished coated fabrics or articles and product thereof



MAX N. NICKO'WITZ, OF FAIRFIELD, CONNECTICUT, ASSIGNOR TO E. I. DU PON'I' DE NEMOURS & COMPANY, OF WILMINGTON,

Patented Feb. 4, 1930 UNITED STATES PATENT OFFICE.

WARE

DELAWARE, A. CORPORATION OF DELA- IPROCESS OF TREATING CASEIN-VARNISH-FINISHED COATED FABRICS 0R ARTICLES AND PRODUCT THEREOF No Drawing.

This invention relates to a process of treating casein varnish finished coated fabrics or articles and product thereof, and more particularly to casein varnish coated articles of manufacture which have been surface-treated with bromine to modify the surface qualities in various respects, as will be more fully described hereinafter.

It is an object of the invention to coat or surface-treat various articles of manufacture with casein varnish so as to modify the surface characteristics and, furthermore, to treat the said varnish with a halogen, preferably bromine, so as to modify the characteristics of the varnish, as for example, by somewhat softening it so that the resulting articles will have a smooth, velvety surface which will not scuff and which will not drag when such surfaces are rubbed or moved over each other. Another object of the invention is to increase the waterproof characteristics of the finish. A further object is to accomplish the aforesaid objects preferably without allowing the brominating or halogenating treatment to penetrate through to the rubber, as it is generally not desired to harden the rubber, the action of bromine in this respect being well known in the priorart. It is astill further object to prepare particularly pliable fabrics with a bromine-treated casein varnish sur-' facing and especially to do this without allowing the bromine to penetrate through to the rubber portion of the fabric, as it is known that bromine has a hardening action upon rubber and this would consequently interfere with the pliability of the fabric.

Further objects will appear as the follow ing description proceeds.

The aforesaid ob ects are accomplished in my lnventlon, and, while varlous embodiments thereof may be made without depart ing from the spirit thereof, the following embodiments have been found by me to be advantageous in practice.

Accordingly, one embodiment consists in the following procedure: A bleached nainsock cotton fabric is taken and the back of the fabric is coated with one spreader coat of a coatlng composltion compnsmg: pale crepe rubber, 40 lbs; zinc oxide, 5 lbs. 3 sul- Application filed November 23, 1927. Serial No. 285,404.

kind of composition; The face is then calendared to a total gauge or thickness of twelve thousandths of' an inch with the aforesaid 'composition, in this case 'the gasoline being left out. The face of the fabric is next dusted with magnesium carbonate as it comes off the calender, and the material is then vulcanized for one hour and thirty minutes at 240- F. The material is then varnished with a varnish made from the following stock formula:

Casein 8000 grams. lrVater 1500 cc. Glycerin 500 cc. Alcohol 8000 cc. Ammonia v 700 cc. Formalin 700 cc.

The varnish is made .up in the following maimeiz' Casein and water are warmed together andallowed to stand over night. Glycerin and ammonia are then added. The casein goes into solution at this point, after which the-alcohol and formalin are added. Before application to the fabric, the above formula is diluted by adding one part of Water to seven of this formula. Thevarnish is appliedto the fabric at about 50 C. After the material is varnished, the varnish is treated with a 4% solution of bromine in carbon tetrachloride and the surface of the material is then neutralized by festooning in an atmosphere of ammonia. By this process, there is produced a rubberizedfabric having a varnish coating, the surface of which is modified by bromine so as to produce the characteristics of velvety smoothness, absence of scufling, resistance to water spotting, retention of pliability, and a certain amount of softening of the varnish.

Another embodiment of the invention consists in the following procedure and product: The'cottonfa'bric isdyed and the spreader coat on'the back is, in this case, omitted.

' the surface of the material.

Either one or two spreader coats of the same type of compound as described above are applied on the face of the fabric and these spreader coats are followed by a calender coat of the same compound to give the desired thickness of rubber coating. Casein varnish is applied at the calender, this varnish having the same composition and being prepared in the same manner as that in the preceding example. The material is then vulcanized by means of dry heat, and, after vulcanizing, the surface is brominated with a 4% solution of bromine in carbon tetra-chloride. The coated fabric is then festooned in an atmosphere of ammonia so that the free bromine and any hydrobromic acid that may be present may be neutralized. A product is formed by this process which is similar to the product of Exam le 1.

s a further embodiment, the procedure of Example 2 is followed, but with the difference that an additional coat or coats of casein varnish are put on after vulcanization but before bromination.

A still further embodiment consists in following the foregoingproceduresbut with the application of two or more coats of casem varnish to provide a total thickness of varnish film or coating sufficient to prevent the bromine, which is later applied, from penetrating the varnish coating and afiecting the rubber underneath, such as hardening the rubber and reducing the pliability of the fabric. These two coats of varnish maybe applied before vulcanization or after vulcanization, or one of them before and one after vulcanization, provided, in the event that both coats are applied after vulcanization, some method such as dusting the rubber surface is used to prevent sticking of the rubber surface to itself.

Another type material may be made by omitting the sulfur and accelerator from the compound and vulcanizing before the application of casein varnish by means of sulfur chloride. The sulfur chloride cure may be effected either by the application of sulfur chloride vapors or sulfur chloride solution to The material is then varnished after neutralizing and the surface halogenized followed by neutralization.

An embossed fabric article may be manufactured by rubberizing a similar kind of fabno of hpplying varnish at the calender the material is first dusted with clay and is then embossed with a suitable pattern. After embossing, a very thin solution of a contrasting colored rubber is applied togive a two-tone effect. The material is then coated with casein varnish, vulcanized, brominated, and neutralized, as described above.

l The coated fabric may also consist of a pyroxylin-coated material finished with casein varnish and subsequently brominated. It

as in theforegoing examples, and insteadv might further consist of an oxidized linseed or Chinawood oil coating finished with cascin varnish and subsequently brominated.

As a result of the foregoing processes, there are producedarticles of manufacture, such as fabrics and coverings, which are provided with a casein varnish coating, surfaces of which are modified by a bromine treatment. I have found that the action of the'bromine is to somewhat soften the varnish, with the result that the varnished surface has imparted to it a velvety smoothness and absence of so-called drag, with the further quality of having a waterproof surface. By baking the Varnish and subsequently brominating this film, I produce a more waterproof finish which does not spot asreadily asan untreated varnished surface. While it is possible, with a very thin film of varnish, for the bromine to penetrate through to the rubber and 1 thus harden it in accordance with the degree of penetration, I prefer to avoid this action by making the casein varnish film continuous and thick enough to prevent penetration by the bromine and thereby to retain pliability. This quality is important, for example, in making a coated fabric which is to be used as a garment, and, accordingly, draped in a suitable manner. C

I prefer to use bromine, but other members of the halogen group may be employed in this invention, and I may also use halogen compounds, such as sulfur chloride and sulfur,

bromide.

In manufacturing the articles, the rubber is calendered on to the fabric by calender rolls in the manner known in the art, and the varnish is spread on the fabric in a known manner by the aid of a doctor blade, this operation being followed by drying, as for example, passing over steam coils and then cooling on a drum. The dusting ofthe clay is also accomplished by the aid of a doctor blade, and the surplus is brushed off. When brominating the casein varnish, the fabric is passed over rollers underneath a hood to remove objectionable halogen vapors, and the coating is performed by a roller partly submerged in the bromine solution.

As many apparently widely different embodiments of this invention may be made without departing from the spirit thereof, it is to be understood that I do not intend to limit myself to the specific embodiments thereof except as indicated in the appended claims. a

I claim:

1. A process of superficially finishing rubs bergoods, which comprises applying a casein varnish coating to the rubber surface and then halogenizing the .varnished surface.

2. A process of superficially finishing cured rubber goods, which comprises applying a casem varnish'coating to the rubber surface and then halogenizing the varnished rubber surface. I

3. A process of superficially finishing casein varnished rubber goods, which comprises halogenizing the varnished rubber surface.

4. A process of superficially finishing rubberized sheeting, which comprises curing the sheeting, applying a solution of casein varnish to the rubber surface, and finally halogenizing the varnished surface.

5. An article of manufacture, comprising cured rubber goods having a coating of halogenized casein varnish.

6. An article of manufacture, comprising cured rubberized sheeting, the rubber surface of which is halogenized and coated with halo,- genized casein varnish.

7. In the preparation of flexible, rubberized fabrics, those steps which comprise the application of a casein varnish coating thereto, and the treatment of such coating with a halogen.

8. A process of superficially finishing rubber goods, which comprises applying to the rubber surface a coating of a coating composition comprising casein varnish and capable of being modified by halogenization, and halogenizing the composition.

9. A process of superficially finishing rubher goods, which comprises applying tothe rubber surface a coating of a coating composition comprising casein varnish and capale of being softened by' halogenization, and halogenizing the composition.

10. A process of finishing rubber goods, which comprises applying a casein varnish coating to the rubbersurface, halogenizing the varnished surface, thereby modifying the surface of the same, and neutralizing the said to surface.

- .11. Aprocess of superficially finishing articles of manufacture, comprising applying to the surface thereof a coating of a coating composition compr sing casein varnish, and r :5 halogenizing the composition.

12. An article of manufacture having 'a coating of halogenized casein varnish.

13. An article of manufacture having a coating comprising baked casein varnish having halogenized surface portions.

14. A process of finishing articles of manufacture comprising casein varnishing the surface, baking it, and then halogenizing the varnished surface. I I

5 In testimony whereof, I aflix my signature.

MAX N. NICKOWITZ.

4' r v a K "CERTIFICATE vOF CORRECTION.

Patent No. 1,746, 162.] Granted February 4, 1930, to

MAX N. NICKOWITZ.

It is hereby certified that error appears in the printed specification of the above numbered'patent requiring correction as follows: Page 3, line 16, claim 6, strike out the words "halogenized and"; and that the said Letters Patent should be read with this correction therein that'the same may conform to the record of the ease in the Patent Office.

\ Signed and sealed this 4m day of March, A. 1). 1930;

M. J. Moore,

(Seal) Acting- Commissioner of Patents. 

